Thermostat.



T. CHAPMAN.

THERMOSTAT.

APPLICATION FILED JIPILII, 1911.

1,034,689, Patented Aug. 6, 1912.

@Wi blames n l I Y ymomias CHAPMAN, .or nerven, coronario;

f Specication of vLetters Patent.

Patented Ang. 6, 191,22.

Application filed April 14, 191.1. Serial No. 621,047.

To all .whom fit may concern:

Be it known that I, THOMAS CHAPMAN, a

citizen cof theUnited. States, residing inthe city and county of Denver and State of Colorado, have invented certain new and useful V Ianproveme'nts in Thermostats; `and I do declare 'the following to be a full, clear, and exact description of the invention, such as Will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to the characters of reference Vmarked thereon, which form a part of this specification. I.

My invention relates to improvement-sin thermostats. v

An important feature of my present improvement consists in the fact that the thermostat bar which bends or changes its shape as the temperature rises and falls in its vicinity, is merely a device for actuating a circuit'closing member, the circuit not pass.- ing through thethermostat bar.

Another important feature of the construction Iconsists in the fact that the upper extremity of the thermosat .bar which actuates the circuit closing member, is insulated from said member, preferably by a piece of glass doubled over the upper extremity'of the bar and 1extending downwardly thereon y a suitable distance.

The mechanism of my improved thermostat is mounted upon an insulating frame Whose upper portion is closed to protect the parts of the mechanism vfrom the Weather,

' while its lower portion is entirely open on thermostatn In, carrying out my invention I suitably -Inount a thermostat bar, composed of two different materials having different ratios of expansion and contraction, on 'a frame composed of non-conducting. material. The thermostat lbar is rigidly secured `at one extremity to the bottom 4of the frame and extends upwardly therefrom, its upper exvis a non-conductor of electricity.

tremityv being free and adapted to move laterally under the influence of the varying temperature in the vicinity of the thermostat. To the top of the frame which is inclosed as aforesaid. -is pivotally connected a depending circuit closing member adapted to be engaged by the free extremity of the thermostat bar.

I employ two alarm devices, each located in -an electrical c ircuit,`the poles of which circuit are respectively connected -with theA circuit closing member and with contacts located on the said frame. The circuit is adapted to befclo-sed through .one ,of these alarm devices when the .temperature rises beyond a certain degree, while the xcircuit is adapted to be closed through the other ala-rm device when the temperature falls beyond a certain degree. The contacts mounted on the frame of the device are adjustable to and from the circuit closing member in order to regulate the d ee of the temperature at which the thermostat bar will ,cause the circuit closing member to -engage the said contacts. Having briey outlined my improved construction I will proceed to describe the same in detail2 reference .being made `to the acF companymg drawing in which is illustrated an embodiment thereof. l l

In this drawing Figure 1 is a vertical section of the device shown in connection with alarm devices. Fig. 2 is a similar section of a modified form of construction. Fig. 3 is a horizontal section taken on the line 3 3, F ig. 2, looking in the direction .of the arrow.

Fig .4 is ya cross-section taken through the lower portion of the frame, locking toward the bottom of the same..

TheA same reference characters indicate the same parts in all views.

'Let .the numeral v5 designate a frame whose Wall is composed of suitable material which 0n this frame is mounted the thermostat bar 6, its two members being secured together by means of rivets 7. The materials employed in this thermostat bar are preferably iron 'and zinc. However, other materials may be employed to equal advantage. One ex' tremity of the thermostat bar 6 is bent at an angle thereto as shown at 8, and Secured within a recess 9 to the bottom ofthe frame by 'means of a bolt 10. The 'opposite exliti tremity of the bar 6 is free` andl provided with a cap 12 of insulating material, preferably glass. To the under side of the top of `member 1'?.

The numeral 21 represents the high temperature alarm device, and the numeral 22 the low temperature alarm device. Each of these alarm devices is located in an electric circuit. The circuit in which the high `temperature alarm device is located may be. Itraced as follows: From one pole 23 of a source of electricity 24C leads a wire 25 to the circuit closing member 17, through the part 13, put in the dotted line position, to a Contact screw 26, thence from this contact screw through a wire 27 to a binding post 28 of the alarm device 21, thence from thev opposite binding post 29 to the said alarm device through a wire 30and the wire 32 to the opposite pole 33 of thesource of electricity. The circuit through the low temperature device 22 may be traced as follows: from the pole 23 of the source of electricity 24,-, through the wire 25 to the part 19 of the circuit closing member, through a contact screw 3X1, when the part '19 is in engagement with the said screw through a wire 35 to abinding post 26 of the alarm device 22, thence from the opposite binding. post l3'? of the said alarm device, through a wire 33 and the wire 32, to the opposite pole 33 of the source of energy 2li, thus completing the circuit.

JV hen the temperature rises beyond a certain degree', the thermostat bar 6 will be caused to move toward the left, carrying the circuit closing member 17 with it, until the part 18 ofthe said member engages the contact screw 215, whereby the circuit will be closed through the high temperature alarm device 21, and give notice of the fact that the temperature in the vicinity of the thermostat is above a certain degree. "W hen the temperature lowers beyond a predetermined degree, the thermostat bar will be caused to move toward the right, causing the part 19 of the circuit closing member 17 to engage the contact screw 3i, whereby the circuit will be closed through the low temperature alarm device 22 and give notice of the fact that the temperature has fallen beyond a predetermined degree.

ln Figs. 2 and 3 l have shown a medilied form of my invention, which modification comprises a frame 39, substantially the same as the frame 5 first described; and a 'thermostat bar l0 of substantially the same construction as the bar 6 disclosed in F ig. l. The lupper or free extremity of this thermostat bar 40 is provided with an insulating capv or crown 42' which interloclrs with the outwardly bent extremities 43 of the two di'erent materials composing the thermostat bar. Depending from the under side of the top al of the frame 39 are two circuit closing members i4 and l5, each of which comprises a support 46 pivotally mounted inthe top of the frame as shown at 47, and having its lower or free extremity bent to form retaining hooks 48. ln each .of these hooks of the depending supports- .46 is mounted an :msulating block or plate 19, preferably composed of glass. Secured to ceachinsulating block 49 'is a contact member 50 composed of material forming a good conductor of electricity, as metal. ln this modified form of my invent-ion l mount two contact screws 51 and -52 upon the same side of the frame, and with which conductors- 53 and 54 of an electric circuit are respectively connected. Upon the opposite side of the frame are mounted similar contact screws 55 and 56 connected respectively with conductors 5? and 58 which lead to the opposite poles of an electrical source not shown.

rll`he operation of the modilied form of construction is substantially the same as that of the first described forni. However, when the thermostat bar 40 moves under the influence of rising or falling temperature conspace between, or electrically connect, the 1 contact screws 51 and 52 or 55 and 56, asv the case may be.

Attention Vis called to the fact that the Contact screws disclosed in the different views are adjustable to and from the circuit closing members, whereby the degree of temperature at which the circuit closing members will be caused to close the circuits may be varied.

As heretofore stated, it must be understood that the thermostat bar in both forms of construction does not form a part of the electrical circuit, since the same is entirely insulated from the elements of the circuit, the said bar serving only to actuate the circuit closing members or impart to them the necessary movement for circuit closing purposes. ill`he insulation of the `thermostat bar from the elements of vthe circuit is ac` complish'ed in the. form of construction disclosed in Fig. l by means of the glass cap 12, and in the form disclosed in Figs. 2 and 3 by means of the glass blocks 49 iuterposed between the contact. strips 50 and the pivoted supporting parts it).

site extremity free, and a circuit-closing as maree@ thermostat barvmounteo'l thereon and having tremity of the thermostat bar, for the purone extremity rigidly secured and its oppopose setforth.

lVntest-imony .whereof I aix my signature in presence oftWo Witnesses.

THOMAS CHAPMAN.

member pivotallymounted on lthe frame and adapted to be engaged and actuated by the free extremity of the thermostat bar, the free extremity of the thermostat bar being provided with a cap composed of insulating material entirely surrounding'- the free eX- Witnesses:-

WILMA H. CooN, E. E, BOWEN. 

